mfd: Add TI LMU driver

TI LMU (Lighting Management Unit) driver supports lighting devices below.

  LM3532, LM3631, LM3632, LM3633, LM3695 and LM3697.

LMU devices have common features.
  - I2C interface for accessing device registers
  - Hardware enable pin control
  - Backlight brightness control
  - Notifier for hardware fault monitoring
  - Regulators for LCD display bias

It contains fault monitor, backlight, LED and regulator driver.

LMU fault monitor
-----------------
  LM3633 and LM3697 provide hardware monitoring feature.
  It enables open or short circuit detection.
  After monitoring is done, each device should be re-initialized.
  Notifier is used for this case.
  Separate patch for 'ti-lmu-fault-monitor' will be sent later.

Backlight
---------
  It's handled by TI LMU backlight consolidated driver and
  chip dependent data. Separate patchset will be sent later.

LED indicator
-------------
  LM3633 has 6 indicator LEDs. Programmable dimming pattern is also
  supported. Separate patch for 'leds-lm3633' will be sent later.

Regulator
---------
  LM3631 has 5 regulators for the display bias.
  LM3632 supports 3 regulators. One consolidated driver enables it.
  The lm363x regulator driver is already upstreamed.

Signed-off-by: Milo Kim <milo.kim@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 259 insertions, 0 deletions

diff --git a/drivers/mfd/ti-lmu.c b/drivers/mfd/ti-lmu.c
new file mode 100644
index 000000000000..cfb411cde51c
--- /dev/null
+++ b/drivers/mfd/ti-lmu.c
@@ -0,0 +1,259 @@
+/*
+ * TI LMU (Lighting Management Unit) Core Driver
+ *
+ * Copyright 2017 Texas Instruments
+ *
+ * Author: Milo Kim <milo.kim@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/ti-lmu.h>
+#include <linux/mfd/ti-lmu-register.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/slab.h>
+
+struct ti_lmu_data {
+	struct mfd_cell *cells;
+	int num_cells;
+	unsigned int max_register;
+};
+
+static int ti_lmu_enable_hw(struct ti_lmu *lmu, enum ti_lmu_id id)
+{
+	int ret;
+
+	if (gpio_is_valid(lmu->en_gpio)) {
+		ret = devm_gpio_request_one(lmu->dev, lmu->en_gpio,
+					    GPIOF_OUT_INIT_HIGH, "lmu_hwen");
+		if (ret) {
+			dev_err(lmu->dev, "Can not request enable GPIO: %d\n",
+				ret);
+			return ret;
+		}
+	}
+
+	/* Delay about 1ms after HW enable pin control */
+	usleep_range(1000, 1500);
+
+	/* LM3631 has additional power up sequence - enable LCD_EN bit. */
+	if (id == LM3631) {
+		return regmap_update_bits(lmu->regmap, LM3631_REG_DEVCTRL,
+					  LM3631_LCD_EN_MASK,
+					  LM3631_LCD_EN_MASK);
+	}
+
+	return 0;
+}
+
+static void ti_lmu_disable_hw(struct ti_lmu *lmu)
+{
+	if (gpio_is_valid(lmu->en_gpio))
+		gpio_set_value(lmu->en_gpio, 0);
+}
+
+static struct mfd_cell lm3532_devices[] = {
+	{
+		.name          = "ti-lmu-backlight",
+		.id            = LM3532,
+		.of_compatible = "ti,lm3532-backlight",
+	},
+};
+
+#define LM363X_REGULATOR(_id)			\
+{						\
+	.name          = "lm363x-regulator",	\
+	.id            = _id,			\
+	.of_compatible = "ti,lm363x-regulator",	\
+}						\
+
+static struct mfd_cell lm3631_devices[] = {
+	LM363X_REGULATOR(LM3631_BOOST),
+	LM363X_REGULATOR(LM3631_LDO_CONT),
+	LM363X_REGULATOR(LM3631_LDO_OREF),
+	LM363X_REGULATOR(LM3631_LDO_POS),
+	LM363X_REGULATOR(LM3631_LDO_NEG),
+	{
+		.name          = "ti-lmu-backlight",
+		.id            = LM3631,
+		.of_compatible = "ti,lm3631-backlight",
+	},
+};
+
+static struct mfd_cell lm3632_devices[] = {
+	LM363X_REGULATOR(LM3632_BOOST),
+	LM363X_REGULATOR(LM3632_LDO_POS),
+	LM363X_REGULATOR(LM3632_LDO_NEG),
+	{
+		.name          = "ti-lmu-backlight",
+		.id            = LM3632,
+		.of_compatible = "ti,lm3632-backlight",
+	},
+};
+
+static struct mfd_cell lm3633_devices[] = {
+	{
+		.name          = "ti-lmu-backlight",
+		.id            = LM3633,
+		.of_compatible = "ti,lm3633-backlight",
+	},
+	{
+		.name          = "lm3633-leds",
+		.of_compatible = "ti,lm3633-leds",
+	},
+	/* Monitoring driver for open/short circuit detection */
+	{
+		.name          = "ti-lmu-fault-monitor",
+		.id            = LM3633,
+		.of_compatible = "ti,lm3633-fault-monitor",
+	},
+};
+
+static struct mfd_cell lm3695_devices[] = {
+	{
+		.name          = "ti-lmu-backlight",
+		.id            = LM3695,
+		.of_compatible = "ti,lm3695-backlight",
+	},
+};
+
+static struct mfd_cell lm3697_devices[] = {
+	{
+		.name          = "ti-lmu-backlight",
+		.id            = LM3697,
+		.of_compatible = "ti,lm3697-backlight",
+	},
+	/* Monitoring driver for open/short circuit detection */
+	{
+		.name          = "ti-lmu-fault-monitor",
+		.id            = LM3697,
+		.of_compatible = "ti,lm3697-fault-monitor",
+	},
+};
+
+#define TI_LMU_DATA(chip, max_reg)		\
+static const struct ti_lmu_data chip##_data =	\
+{						\
+	.cells = chip##_devices,		\
+	.num_cells = ARRAY_SIZE(chip##_devices),\
+	.max_register = max_reg,		\
+}						\
+
+TI_LMU_DATA(lm3532, LM3532_MAX_REG);
+TI_LMU_DATA(lm3631, LM3631_MAX_REG);
+TI_LMU_DATA(lm3632, LM3632_MAX_REG);
+TI_LMU_DATA(lm3633, LM3633_MAX_REG);
+TI_LMU_DATA(lm3695, LM3695_MAX_REG);
+TI_LMU_DATA(lm3697, LM3697_MAX_REG);
+
+static const struct of_device_id ti_lmu_of_match[] = {
+	{ .compatible = "ti,lm3532", .data = &lm3532_data },
+	{ .compatible = "ti,lm3631", .data = &lm3631_data },
+	{ .compatible = "ti,lm3632", .data = &lm3632_data },
+	{ .compatible = "ti,lm3633", .data = &lm3633_data },
+	{ .compatible = "ti,lm3695", .data = &lm3695_data },
+	{ .compatible = "ti,lm3697", .data = &lm3697_data },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ti_lmu_of_match);
+
+static int ti_lmu_probe(struct i2c_client *cl, const struct i2c_device_id *id)
+{
+	struct device *dev = &cl->dev;
+	const struct of_device_id *match;
+	const struct ti_lmu_data *data;
+	struct regmap_config regmap_cfg;
+	struct ti_lmu *lmu;
+	int ret;
+
+	match = of_match_device(ti_lmu_of_match, dev);
+	if (!match)
+		return -ENODEV;
+	/*
+	 * Get device specific data from of_match table.
+	 * This data is defined by using TI_LMU_DATA() macro.
+	 */
+	data = (struct ti_lmu_data *)match->data;
+
+	lmu = devm_kzalloc(dev, sizeof(*lmu), GFP_KERNEL);
+	if (!lmu)
+		return -ENOMEM;
+
+	lmu->dev = &cl->dev;
+
+	/* Setup regmap */
+	memset(&regmap_cfg, 0, sizeof(struct regmap_config));
+	regmap_cfg.reg_bits = 8;
+	regmap_cfg.val_bits = 8;
+	regmap_cfg.name = id->name;
+	regmap_cfg.max_register = data->max_register;
+
+	lmu->regmap = devm_regmap_init_i2c(cl, &regmap_cfg);
+	if (IS_ERR(lmu->regmap))
+		return PTR_ERR(lmu->regmap);
+
+	/* HW enable pin control and additional power up sequence if required */
+	lmu->en_gpio = of_get_named_gpio(dev->of_node, "enable-gpios", 0);
+	ret = ti_lmu_enable_hw(lmu, id->driver_data);
+	if (ret)
+		return ret;
+
+	/*
+	 * Fault circuit(open/short) can be detected by ti-lmu-fault-monitor.
+	 * After fault detection is done, some devices should re-initialize
+	 * configuration. The notifier enables such kind of handling.
+	 */
+	BLOCKING_INIT_NOTIFIER_HEAD(&lmu->notifier);
+
+	i2c_set_clientdata(cl, lmu);
+
+	return mfd_add_devices(lmu->dev, 0, data->cells,
+			       data->num_cells, NULL, 0, NULL);
+}
+
+static int ti_lmu_remove(struct i2c_client *cl)
+{
+	struct ti_lmu *lmu = i2c_get_clientdata(cl);
+
+	ti_lmu_disable_hw(lmu);
+	mfd_remove_devices(lmu->dev);
+	return 0;
+}
+
+static const struct i2c_device_id ti_lmu_ids[] = {
+	{ "lm3532", LM3532 },
+	{ "lm3631", LM3631 },
+	{ "lm3632", LM3632 },
+	{ "lm3633", LM3633 },
+	{ "lm3695", LM3695 },
+	{ "lm3697", LM3697 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ti_lmu_ids);
+
+static struct i2c_driver ti_lmu_driver = {
+	.probe = ti_lmu_probe,
+	.remove = ti_lmu_remove,
+	.driver = {
+		.name = "ti-lmu",
+		.of_match_table = ti_lmu_of_match,
+	},
+	.id_table = ti_lmu_ids,
+};
+
+module_i2c_driver(ti_lmu_driver);
+
+MODULE_DESCRIPTION("TI LMU MFD Core Driver");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL v2");